Aer refrigerating apparatus



March 13, 1945. c uc 2,371,129

AIR REFRIGERATING APPARATUS Filed Oct. 4, 1943 2 Sheets-Sheet 1 March13, 1945. G. N. CROUCH AIR REFRIGERATING APPARATUS 2 Sheets-Sheet 2Filed Oct. 4, 1945 1 1 I r I JIIIIIIIIGIII I amen WM Patented Mar. 13,1945 UNITED STATES: PATENT OFFICE.

2,371,129 7 Am REFRIGERATING ArPARATUs Garland N. Crouch, Oklahoma city,Okla. Application October 4,1943, Serial No. 504,940

2 Claims. (01. 62-131) This invention relates to the class ofrefrigeration and pertains particularlyto an improved air chilling orrefrigerating apparatus for use in situations whereit; is desirable ornecessary to maintain the air at'a low temperature.

The primary object of the present invention is to provide an airchillingor refrigerating ap paratus which is designed primarily for use in foodtransporting vehicles and more particularly in interstate trucks whichare employed for carrying meats and other perishable food, in whichanovel: construction makes possible the reduction of air temperatures toa degree which will preserve the perishable foods and maintain such lowtemperature overa relatively. long period of time ata minimum cost. r 1l Another object of the invention is to provide an air refrigeratingapparatuswhich is so constructed that by the use of wet ice and salt ordry ice with a low horsepower air circulatin motor capable 'of runningoff of thejusualwvehicle storage battery, the interior air of a truck orsimilar vehicle may quickly be reduced to a-very low temperature andsuch low temperature maintained without re-charging the apparatus withice for a relatively long period.

Still another object of theinvention is to provide in an apparatus ofthe-characterstated, a

novel construction ofheat transfer unit which.

causes air circulating therethrough to passalong a, tortuous pathway soas. to obtain maximum contact with surfaces chilledby the refrigerantmedium to effectthe maximum transfer of heat from the airtosuch mediumand conse- -quent reduction of the lair temperature to..the

desired degree. l i l v 1 A still further objector the invention ,is toprovide in'an air refrigerating apparatus of the character stated, anovel'assembly of the parts by which the maximum of efficiency of theapparatus is obtained with a minimum; utilization of space within thetransportation structure in which the apparatus isi-disposedi.

The inventionywill be bestunderstood from a consideration of thefollowing detailed description taken in connectionwith the accompanyingdrawings, it being understood however, that the invention is not to beconsidered as limited by the specific illustration or description butthat such illustration and description constitutes a preferredembodiment of the invention.

Inthedrawings: I N Fig, l is a view partlyiin vertical longitudinalsection and partly in elevation through the apparatus embodying thepresent invention and a ings, the numeral I generally designates faportion of the front end of a vehicle in which the present apparatus isdesigned to be used, such as a truclg. The numeral 2 designates aportion of the top or roof of the truck while a portion of the frontwall is indicated at 3 and a portion of the bottom or floor is indicatedat 4.

Such structures when designed for transporting meats or other perishablefood have a slat false bottom or floor 5, and for the setting up of thepresent apparatus in such a structure, this false bottom or floor isprovided with an open area in the forward part of the structure in whichis set a moisture or condensate receivirigpan ortray 6 and in this traythe air refrigerating apparatus is located,- as shown.

The refrigerating apparatus ofthe present invention comprises afluid-tight housing H, here shown as being of rectangular constructionalthough it may be of any other suitable form to adapt to the interiorof the truck or other wheeled vehicle in which it is placed. Thishousing is here'shown as having the front and rear side walls I and 8,respectively, the side walls 9, bottom wall l0. and top H. The topwallII is provided adjacent one side of the housing with an air inletopening l2 while adjacent the opposite side of the housing the top wallhas. formed through the front portion thereof the air outlet opening l3.

Within the housing there is disposed a heat character T. This unit is inthe form of a casing which conforms in outline generally to the form ofthe housing in which .it is located this casing consequently being ofgenerally rectangular] form and haVing-the'tOp. bottom and end walls, l5and I6 respectively,and the front and rear side walls I! and I8,respectively. The top and bottom walls 14 and i 5 are secured to theadjacent edges of the side and end wallsin a suitable manner to ensureagainst the leakage into the casing of fluid from the housing H and theescape of air from the casing into the housing. The casing of the heattransfer unit isshown as having a substantial length which is directedtransversely of. the vehicle in whichthe struc ,openingl3 to form thedeflector wall 26.

ture or apparatus is mounted and extending through the casing from thefront to the rear walls I! and I8 and through such walls, are open-endedtubes l9 which are of relatively large diameter and, are formed like thewalls of the casing of a relatively thin metal so as to obtain a readytransfer of heat through the metal from the air to the refrigerantfluid.

The tubes [9 have their axes directed longitudinally of the vehiclestructure in which the apparatus is located and. it will also beobserved upon reference to Fig. 2, that these tubes are arranged in rowsextending both horizontally and vertically and that such rows aregrouped or located close together so that the tubes of any one row willbe positioned or located partly between adjacent tubes of an adjacentrow. With this arrangement it will be seen that air will not passhorizontally or vertically through the casing between the tubes alongstraight paths but must be deflected by the tubes and, therefore,'al1 ofthe circular surface of each tube will'be bathed in the air and amaximum of heat transfer will be obtained from the air within the casingto the refrigerant fiuidlying within and flowing through the tubes-inthe manner hereinafter stated.

The top wall M of the heat transfer unit casing has formed therethroughthe air inlet and air outlet openings indicated respectively by thenumerals and 2|. over and in register with the air inlet opening 20 isan air inflow pipe 22 which has its other end secured to the top Wall llof the housing in the inlet opening l2.

Secured to the underside of the top ,wall H of the housing adjacent theair outlet opening 13 is a box 23 which hasa bottom wall 24 providedwith an opening25 which is offset from the opening [3. This bottom wall24 is angled upwardly Secured to the top wall 14 through the portionunderlying the air outlet As shown in Fig. 1, the box 23 to which thecold air flows from the unit T, overlies the outlet opening 13anddischarges therethrough.

The numeral 21 designates the air outflow pipe 2 from the heat transferunit and the lower end ofthis pipe is connected over the opening 2| inthe top wall I4 of the unit T, while the upper end of this pipe isconnected in the opening 25 of therefrigerat'ed air receiving box 23.

The box 23 constitutes a housing for a fan scroll 28 and there ismounted upon the top wall H of the housing H an operating electric motor23 for this fan, the shaft of which motor is con- 5 nected with the fan,as shown, and the fan is rotated so as to draw air upwardly through thepipe 21 from the heat transfer unit and force it out through the opening13.

As shown in Fig. 1 and Fig. 2, the heat transfer unit is of a size tohave a substantial space around it between its side and end walls andthe adjacent walls of the housing so that a free circulation ofrefrigerant medium, which may be either salted wet ice or dry ice, canbe had and as shown, the heat transfer unit is submerged in such'medium.The refrigerant here illustrated is indicated by the character R and inaddition to completely submerging the unit T, it extends a substantialdistance up in the housing around the pipes 22 and 21.

Connected with the top wall ll of the housing over the air outletopening I3 is a pipe 30 which extends upwardly-and terminates in theelbow and reduction coupling 3| which is directed reartil wardly in thevehicle and is connected with a distributing conduit 32. This conduit 32is preferably of rectangular cross-section as shown, and extends fromthe front end of the vehicle to a point adjacent the rear end thereofand is open at its rear end as shown at 35 in Figure 3.

At intervals along the length of the conduit 32 lateral outlet openings34 are formed which are covered by the sliding gates 35. These gates areemployed to regulate the circulation of the refrigerated air through thevehicle.

In order to facilitate the removal of condensate from within the heattransfer unit casing, an end wall 16 thereof is provided with a draintube 36 as shown in Fig. 2. This tube passes through the space betweenthe wall It and the adjacent wall of the housing and discharges into thepan 6. This pan has a drain pipe 31 which passes downwardly through thefloor 4 of the vehicle, so that the drainage from the pan passes out tothe ground. There is also providedgas shown in Fig. 2, a valved drainpipe 38 for the housing from which the refrigerant liquid can be drawnoff as desired.

The top wall I l of the housing H has a hinged door39 by which access isbad to the interior of the housing for the stocking or charging of thesame with the necessary refrigerant medium.

It will be readily understood that the refrigerating apparatus of thepresent application may from 800 to 1000 pounds of wet ice and the unitis capable of moving 250 feet of air per minute and when the brinerefrigerant within the housing has a temperature of zero, of reducingthe air temperature from F. to 20 F. and maintaining the' air at thislow temperature for not less than 36 hours. Proper circulation of aircan be maintained through the apparatus by the single fan operated by amotor capable of being run by an ordinary storage battery such as iscommonly used upon trucks. i

As will be readily apparent from the foregoing description of theinvention, when the apparatus is set up for use and the'motor 29 hasbeen set in motion, the fan 28 will draw air-in through the pipe 22 intothe heat transfer unit where it will flow through the casing of thisunit and around the several tubes 19 togive up its heat to therefrigerant medium with which the housing is filled. This medium, ofcourse; not only surrounds the casing of the heat transfer. unit butalso fills the tubes of such unit. While ordinary convection currentswill be set up in the "refrigerant medium as the same absorbs heat fromthe air so that colder portions of the medium will take the place ofthat which has become warmed and tends to rise, the movement of thevehicle, particularly when starting and stopping or when accelerating ordecelerating its closed casing, said casing having atop wall providedwith remotely spaced air inlet and air outlet openings, a pipeconnecting the casing air inlet opening with said housing inlet opening,an air conduit connecting the casing outlet opening with the housingoutlet opening, an air circulator within said conduit for drawing airthrough the casing and discharging it through the housing outlet, a.relatively long air distributing conduit connected at one end with saidhousing outlet for the discharge of refrigerated air at a remote pointfrom the housing and provided with a plurality of side wall air outletopenings, and a shiftable gate movable relative to each of said openingsfor controlling the escape of air therethrough.

2. A heat transfer unit for a refrigerating apparatus of the characterdescribed, comprising a casing designed to be submerged in arefrigerating medium, said casing having top, bottom, side and endwalls, a plurality of open end tubes extending horizontally through thecasing becasing to the opposite end, an air inlet means leading into thecasing adjacent one end, and an air outlet means leading from within thecasing adjacent the other end.

GARLAND N. CROUCH.

